I know, not very helpful... Try google, I believe there are some scripts out there._________________"Those who deny freedom to others deserve it not for themselves." - Abraham Lincoln
Free Culture | Defective by Design | EFF

# Copyright 1999-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

EAPI=4

DESCRIPTION="a FUSE based MTP filesystem designed to make exchanging files between Android devices and Linux"
HOMEPAGE="http://research.jacquette.com/jmtpfs-exchanging-files-between-android-devices-and-linux/"
SRC_URI="http://research.jacquette.com/wp-content/uploads/2012/05/${P}.tar.gz"

I don't think that Galaxy S3 is the problem. This is the new recommendation by Google for new devices under ICS.
It makes sense, because virtually with MTP you don't have to use FAT32, the use of modern filesystem like ext4 is possible => no more limitation on filesize. Plus, when connecting the device on a computer, the filesystem is still avalalble on the phone unlike USB mass storage.

# Copyright 1999-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

EAPI=4

inherit eutils

DESCRIPTION="a FUSE based MTP filesystem designed to make exchanging files between Android devices and Linux"
HOMEPAGE="http://research.jacquette.com/jmtpfs-exchanging-files-between-android-devices-and-linux/"
SRC_URI="http://research.jacquette.com/wp-content/uploads/2012/05/${P}.tar.gz"